PSYCH 130 Lecture Notes - Lecture 4: Random Assignment, Confounding, Dependent And Independent Variables

• School: UCLA
• Department: Psychology
• Course: PSYCH 130
• Professor: elizabethdarvick

Document Summary

Make sure there are no systematic differences between groups except the iv. Confounding variable: ev that varies systematically with the levels of the iv. Everything except the iv and dv is an extraneous variable (ev) Confounding variables prevent us from being able to determine whether the iv is what truly caused changes in the dv. Prevents systematic differences between groups in the iv. Long terms effects on participants (esp in development) Longitudinal design: study the same individuals over a long period of time. Not necessarily lifetime; just over a period of time with measurements at various time points. Subject mortality: participants may drop out of the study. Each subject participates as their own control. Individual differences accounted for at different time points. Cross sectional design: study groups that differ in age; test at the same time. Cohort: group of people who go through a similar experience at the same time.